You should definitely get a photo of the Eiffel Tower, just don't spend an absurd amount of money and time waiting in line to go up to its observation deck. Because you know what any photo of Paris from up there will be missing? The Eiffel Tower!
Instead, get epic views of the City of Light from the Terrasse du Printemps Haussmann — a free terrace on top of the famous Printemps department store.